Valve mechanism for automatic liquid weighing sgales



March 29,` 1932. W E- COPER 1,851,348

VALVE MEGHANISM FOR AUTOMATIC LIQUID WEIGHLG scALEs Filed Dec. 13, 1929 22 I6 J4 :s:

C @Y Q FIG.

W /5 Z0 I I2 J7 ,S l \Y f ""1 I3 Y Egg J0 l J /M c" 25 WPHC/rr l INVENTO veo Patented iMar.l 29,1932? i :'-IIIJLIAIIIr COOPEROF.ABROOKLYN, NEW YORK;ASSIGNOR,TOiAMERIGANMACHINE 8a. FOUNDRY COMIPANY,1A GORPORATIOANOF -'NEW'..JERSEY MECHANISM'FOR AUTOMATIC LIQUID 'WZEIIG-IHING:`SCALES.`

' This inventionfrelates to: Nalveimechanism A'for automatic, liquidfweighing,fscales for fthe pumposez of; filling; containers. The'fgene'ral 'objectief .thepresentinventiorr is to'eliminate certain sources of inaccuracy in machines'of thisj'type When the containers-arcifilled ldirectly 4fronnsupply'vesselthe pressure at the discharge nozzle is greatest when the vessel is full and least when the vessel is nearly empty thus, since the rate of flow is greatest when the pressure is greatest, more liquid will pass through the nozzle from the time the valve starts to close due to tilting of the scale up to the time when the valve is fully closed, with the result that the containers first filled are slightly heavier than those last filled.A

Also, since` inaccuracies due to therflow of liquid after the discharge valve starts to close, and due to drip from the discharge valve, are approximately proportionalto the capacity of the valve andthe drip surface thereof respectively, a relatively large percentage inaccuracy results when a small container is filled from a large nozzle provided with a large valve. A similar inaccuracy results when a nozzle intendedfor slow iowingmateria-ls is employed in filling ywith a free lowing liquid. The main object of the present invention is to eliminate such inaccuracies,

With these and other obj ects not specifically mentioned in view, the invention consists in certain constructions and combinations which will be hereinafter fully'described and then 'more particularly pointed out in the claims hereunto appended.

To the end of el'ecting `the above and other objects., there is provided in the best constructions utilized in carrying out the invention, a valve mechanism comprising a main valve of relatively large capacity, and an auxiliary valve of relatively small capacity carried by the main valve `for decreasing drip. The best constructions further provide means for maintaining a substantially constant pressure of liquid behind the main valve, whereby the ow of liquid after the valve=starts to close will remain the same for each container filled. Preferably, the auxiliary valve is made removable and replaceable by another of different capacity. The .means above freferredifto :maybe:widelyvairiediinl construtioniwitln the scope? ofuthe fclaims,"fort the particular -structureiseleeted :to illustrate :the linvent'ron 4'is butfone of manyipossible concrete fernbedi- `ments oflt'hesame. Thefinvfention',itherefore,

iismotto' fbe :restrict'edzto'the preci'seldetaiilsrf :the structure V:shown andfdescribed. In` theY accompanying" drawings Figs l is afse'ctional."elevlationyo tion; and

'Fig; 2Iis aYdetailviewincross/#sectionl bflthe o valve-"12 Leontrolledxbyvr a'flo'at 13 in the tank.

Thefloatl islsuspendedrom a'double armed y weight Q2 by Ywhich the devel l'f v'the liquidB in tank l0 canfbe accurately adjustedbetween given fliniits- -accordingft`-the` dischargepressure desired. Fluid from 'tank' f10jpasses through pipe 23 into adischarge'valwjhous-y into container Af:v'vhen;"the dischargevalve is'op'en. Y l

'fThe discharge ofi liquid *from* honsingfQl to the -containeri-A tz'lnefilldv is controlled' byv a o main discharge valve26pro'vidd with a "stem 27.' The stfeniQ'I' is guiddfinithesteni 29 'of' l coupling 30 and` fastened 'to Ethe maglietlcore 3l- `movable withinthe Asel'enoi d: '395 ithercore 81' descen'ding and thereby7 closing valve' 26 by"gravity andfbyl the -afctionof a spring-'33 when 11o-electric "current "owsthroulghf-the y Y p fi adefvice -constructedlun accordancewith fthe' inven-V coil 32. The circuit of coil 32 is controlled by a contact attached to the scale beam of the liquid dispensing scale (not shown) in such l a manner that the circuit automatically opens at the moment the scale beam has reached its balance position, thereby causing the valve 26 to shut off the supply of liquid as soon as the container A has been filled to the desired weight, and lea-ves it closed until an empty container is substituted for the filled one.

In order to decrease drip and other sources of inaccuracy such as those already mentioned, an auxiliary valve 34 is removably secured to the face of the valve 26 by means of a threaded stem 34a screwed into a threaded aperture on the main valve stem 27 so as to seat the valve 34 in the orifice of a discharge nozzle 25. This nozzle is screwed onto the end of housing 24 and thus is readily adjustable for perfect seating and is removable to change the valve seat in said orifice. When the scale is being adjusted for a dii'erent size of container or for a different kind of liquid, the nozzle and valve 34 can be easily removed and replaced by a set providing a different size orifice suited for the new conditions.

Thus, in filling small size containers operating with free flowing liquid, by employing 5:3 the above described construction, a small valve 34 may be used and the amount of fiow and drip, after the valve starts to close, correspondingly reduced so that the percentage inaccuracy due to these causes is not substantially greater than when filling large containers.

It will be noted that the two valves 26 and 34, when closed, provide a chamber of very small capacity which serves to catch the drip 4l@ from the large valve and which also makes for greater accuracy by relieving the auxiliary valve 38 of the pressure of the liquid from the vessel l0, thus avoiding increased drip or slight leakage due to pressure of the liquid. Indeed, there would be ylittle tendency of liquid in the small chamber between the two valves to flow past the valve 34 even though the valve were not quite tight on its seat since suchl flow would be opposed by the adherence of the liquid to the chamber walls and valve l surfaces, and the tendency to form a vacuum in said chamber.

What is claimed is: l. Valve mechanism for automatic liquid weighing scales comprising a valve stem, a

main discharge valve of relatively large capacity immovably mounted on said stem, an auxiliary valve of relatively small capacity carried by the main valve beyond said main valve in the direction of liquid iiow to decrease drip, a valve housing having a seat for said main valve, and a nozzle removably secured to said housing and seating said auxiliary valve, said auxiliary valve being rel movably secured to said valve stem.

2. Valve mechanism for automatic liquid weighing scales comprising a Amain discharge valve of relatively large capacity, and an auxiliary valve of relatively small capacity carried by the main valve beyond said main VILLIAM E. COOPER.

valve in the direction of liquid How to decrease drip, said auxiliary valve being re- 

